Mechanism for grinding



Dec. 5, 1944. M; H. ARMS MECHANISM FOR GRiNDING Filed Aug. 13, 1940 3Sheets-Sheet 1 Dec. 5, 1944. M. H. ARMS 2,364,120

MECHANISM FOR GRINDING Filed Aug. 13, 1940 5 Sheets-Sheet 2 1a o Q Jf '7D 9 4. M. H. Arms 2,364,120

MECHANISM FOR GRINDING 44 Filed Aug. 13; 1940 :5 Sheets-Sheet s PateniedDec. 5, 1944 UNITED STATES PATENT ,IOFFI'CE MECHANISM FOR GRINDIN GMerton H. Arms, Springfield, Vt, assignor to Bryant Chncking GrinderCompany, Springfield, Vt., a corporation of Vermont Application August13, 1940, Serial No. 352,380

12 Claims.

This invention relates to the grinding of work and is particularlyconcerned with internal grind- One of the features of the inventionrelates to a multiple selective control of the feed of a grinding wheelspindle whereby the feed of the grinding wheel may be controlledselectively in accordance with a plurality of definite laws of action atdifierent times, and if desired for operation on different portions of apiece of work.

One specific example of the use of such a control is found in grindingthe bores of internal combustion engine cylinders particularly where theengine head is made of a relatively light weight alloy and has athreaded connection with the barrel portion. In'such work a very smalldeparture from accurate cylindricity has been found desirable,particularly adjacent to the harrel ends. Such departures may also befound 'desirable at other portions. In accordance with this invention asapplied to this type of work, the rough grinding may be cylindrical, thefinal grinding, only, providing for such departures from cylindricity.

An object of the present invention, therefore, is to provide a methodand mechanism for effectmg such multiple feed control in a selectivemanner.

For a more complete understanding of thisinvention, reference may be hadto the accompanying drawings in which Figure l is a front elevation of'agrinding machine embodying the invention as applied to the grinding ofengine cylinder bores.

Figure 2 is a diagrammatic sectional view on line 2--2 of Figure 1, thedeparture from cylindrical of the work and the wheel being greatlyexaggerated.

Figures 9 and 10 are views similar to Figures 7 and 8, respectively, butshowing a modifledcoi'istruction and arrangement.

Figure 11 is a fragmentary longitudinal section V as showing muchexaggerated the cylinder wall contour produced by the mechanism ofFigures 9 and 10.

Figures 1 and 4 illustrate an internal grindingmachine of the well knownBryant type and as shown generally in the Arms Patent No. 2,176,985. Itcomprises a base I, a rotary work support 24 and a rockable and axiallymovable wheel carrier 3.

This wheel carrier is mounted for its rocking motion on an overhead axisof a cylindrical control bar 4 and the lower end of this carrier isprovided'with an extension 5 which rests by gravity against a suitablefeed control mechanism along which this extension rides during the axialtraversing motion of the carrier 3. This carrier 3 3 supports a grindingwheel spindle 6 carrying a grinding wheel I at one end and a drivingpulley 8 at the other. A driving belt 9 passes around the pulley 8 andabout suitable idlers Ill and H, and about a drive pulley IQ of a motorI3.

As shown best in Figures 4 and 5, the extension 5 carries a pair ofabutment members!!! and 2! at difierent radial distances from the axisoi. the

control bar 3, either of which may be employed;

as desired. The abutment member 20 is shown as a bar of circular crosssection clamped in position by means of a clamping jaw 22 which may besecured in position as by bolts, one of which is shown as. at 23.The-abutment 2i is shown as a flat bar secured in adjusted position byscrews such as it and adjustable substantially horizontally as byadjusting screws 25 provided with lock nuts rt. Both the abutments 2cand 2i extend for a substantial distance generally parallel to themember i so that they control the angular position of the wheel support3 during the traverse of the grinding wheel along the interior of thework. Cooperating with the abutment 2B is a feed bar 30 which may carrya cam roller 3| at its rear end abutting the abutment 20. Similarly theabutment 2| may be engaged by a follower 32 Ma feed bar 33. The feed bar30 may have a threaded shank portion 35 for engagement within a feed nut36 journaled aga nst axial motion in asultable portion of the machinebed and the bar 33 may have a threaded extension 31 engaging in a nut 38similarly held against axial motion. Suitable means may be provided forturning these nuts 36 and 38 as desired to move their respective. fe'edbars axially. Thus the nut 36' may have keyed thereto ahand wheel 40.provided with handles 4| thereon and for automatic feed it may have aratchet ring .42 secured thereto for engagement by a feed ratchet whichmay, it desired, be carried by a re'ciprocatory bar 43 (Figure 1)actuated from within a casing 44. A memher 408 which may be rotated withthe wheel40 or latched in stationary position may be provided with amicrometer feed pinion having an actuat-' ing handle 4|l| and it mayextend over the ring 42 and act as apower feed limit stop when themember 408 is unlatched. The nut 38 may have I secured thereto a gear 45which may be connected through an idler gear 46 with a gear 41 on a feedshaft 48. This shaft 48 may be provided with a hand wheel 48 similar tothe hand wheel 48, and a ratchet mechanism micrometer hand feed, andfeed limit stop similar to that applied to the nut 38.

In Figure a modification is'shown in which the lower feed abutment at 50comprises a bar of circular cross section, while the'upper abutment 5|is formed as a fiat bar. A bar of circular cross section permits angularadjustment when worn to present a fresh guide surface. The fiat bar 5|may be found more convenient when there is considerable irregularity ofcontour. Either may be formed readily by a turning operation.

For internalcombustion engine cylinders of the type where thecylindrical barrel is secured to the head by a threaded connection, asillustrated in Figure 3, the barrel being shown at Siand the head at 56,in order to allow for expansion under normal working conditions of heat,it is found desirable to slightly enlarge the bore of the barrelinwardly from its head end and to have a reduced internal diameter atthe extreme end. It is also found desirable to form the open end of thecylinder as at 51 with a slightly decreased 1 and 4, the barrel issupported ina suitable fixture 60 (Figure 2) by which it may be clampedin position with respect to'the work holder. 2,. and the grinding wheelI is caused to traverse it. Because of the very slight variation fromtrue cylindrical contour desired in the finished barrel,

this invention provides for rough grinding the interior to cylindricalcontour and then producing the slight departures from cylindricalcontour at or adjacent to the ends of the barrel in the finish grinding,and preferably with the grinding wheel contour slightly modified from 5the cylindrical contour desirable for-best results during ,the roughgrinding.

A wheel truing diamond is illustrated at 65, this being positionedbeyond the outer end of the work so that the wheel may be trued in anextended portion of its traverse where it is clear from the'work and inwhat may be termed the truing range of the wheel traverse asdistinguished from the working range during which the wheel is incontact with the work. Assuming that the work is placed in the workholder for the rough grinding operation, the grinding wheel I,preferably trued to cylindrical contour, is caused to traverse thecylinder, the position of the wheel are shown very much exagger-.

- position of Figure 7 and traversed with a short with respect to thewall of the work being ad-" justed as desired through that one ofthe'feed mechanisms which is provided with the abutment arranged forproducing a straight line traverser The wheel is fed into the work tothe extent desired for the rough grinding operation by a suitableoperation of the selected feed mechanism. For example, the machine maybe equipped to operate as shown in-my Patent No. 2,176,985previouslymentioned. If desired, the wheel may be trued cylindrical asoften as desirable to preserve cylindrical contour and a good grindingface, through an extended traverse of the wheel, the traverse beinglinear and in line with the traverse within the work, the diamond 65being moved into position for the truing operation in any suitablemanner.

After the rough grinding has-been completed, the feed mechanism for therough grinding is retracted and the feed mechanism for finish grindingbrought into operation. It will be assumed'that this finish-grindingfeed mechanism is that employing the abutment 20 of circular crosssection, although as before stated, it might be the flat bar abutment ifdesired. The finish abutment, however, is not the same diameterthroughout, but may be formed as shown in Figures 6, 7 and 8 with acylindrical intermediate portion 10, a tapered portion 1|, and a smallerdiameter cylindrical portion 12 adjacent thereto toward one end of theabutment. At the other side of the cylindrical portion 18 is an enlargeddiameter portion 13 formed by a pair of tapered walls 14 and 15. Beyondthis portion 13 is a smaller diameter portion It between taperedportions l1 and I8.

The wheel being retracted from the work into the position shown inFigure 8, and the feed mechanism including the follower roll 3| being incontact with the bar 20 at the'position shown in Figure 8, an outwardtraverse of the wheel carrier will bring the smaller diameter portion 16to the follower and as the traverse away from the work continues, thegrinding wheel will be trued to the contour shown in Figures 6, 7 and 8,having a central large diameter portion 88 and tapered to a smallerdi'ameterat opposite ends as at 8|. The wheel being thus trued, traverseof the work is again commenced. Preferably the wheel is moved into thework and then fed thereagainst in the stroke, as by hand control, untilthe wheel'has been fed in sufficiently to engage theportion on a moreextended traverse, at which time the normal power grinding traverse offull length is started and the finish grinding completed with the fulltraverse. The intermediate portion 85 is cylindrical and a reducedsloping portion 86 is ground adjacent to the open end of the barrel.Near to the opposite end of the barrel, there is ground an enlargeddiameter portion 83 and at the end an inwardly sloping portion- 84. Thefollower roll 3| engages the enlarged diameter portion 13 of theabutment when working on the end of the cylinder barrel adjacent to thehead and engages the portion II to form the taper contour adjacent tothe open end of the cylinder. Thus the finish grinding operationproduces the cylinder with its main portion truly cylindrical and itsend portions having the slightly different but desired contours for thecompleted cylinder.

In Figures 9 and 10 is shown a modification in which the cylindricalrough grinding and modified finish grinding contours may be producedwith a single grinding wheelfeed mechanism. In this case a pair oftruing devices 90 and 9| are employed, one of these fortruing the wheeltocylindrical contour, and the other for truing it to a convex contour.The abutment 93 which 7 determines the angular position of'the wheelcar- ' aso eiso rier, andthus the ,feed position of the wheel withrelation to the work,'is provided with a cylin-r length. A portion ofthis cylindrical contour length as from a to b corresponds to the grinding traverse of the work. Another portion of this cylindricalcontourifrom a to c is for an extended traverse duringwhich the truingdevice when moved into operative position may true the wheel tocylindrical contour, this being the contour of the abutment between theportions a and c. This is the position shown in Figure 9. This abutment93 has another portion between the points "d and e which is of decreaseddiameter. when the grinding wheel traverse is extended so that thefollower 3'] engages this portion of the bar a, the wheel is so guidedpast the truing device 9|; which may be brought in operative relation tothe grinding wheel, to true the grinding wheel to the convex contourillustrated in Figure 10 drical contour for the greater portionot itsanisms for producing and controlling a teed mo-- tion of said shaft,each of said controlling mechanisms including a template for controllingsuch feed motions automatically in' accordance'with the traversepositions; of saidwheel and the contour of the controlling template,said templates having diite'rent' controlling contours, and means Y forselectively presenting one or another of said for the finish grindingoperation. When the wheel of thiscontour is then applied for the finishgrinding and the wheel traverse is limited to the distance a-b so thatthe wheel does not clear the work at either end, the resultant contouris that shownin Figure 11, where there is an intermediate centralportion'of true cylindrical contour and tapered end portions 'at 95 and98. The feed will then be retracted before the traverse is extended toremove the wheel from the work, so I that the finished wheel contourremains as shown in Figure 11. While this contour is not as desirable asthat shown in Figures 2, 3, 6, 7 and 8, it may in-some cases serve thedesiredpurpose.

While as shown, the departures from cylindrical contourtaper are insubstantially straight lines, and the grinding wheel for finish grindingis similarly arranged, this is -not essential as the changes of contourmay'be'aiong curved instead of straight lines if desired.

It will be noted that the various contours may be made on the same pieceor work with a single chucking of the work so that these variouscontours are produced in definite accurate relation one to the other.

It should be evident to those skilled in the art that various otherchanges and modifications might bemade without departing from the spiritor scopeof this invention as defined by the appended claims.

I claim:

1. A grinding machine having a work support,

a grinding wheel shaft for suppor ing a grinding wheel, means forrelatively reciprocating said whe'el shaft and work support to cause agrinding mechanisms in feed and controlling operative positions wherebyeach of said mechanisms may be rendered effective for the same workpiece with a single chucking of said work piece.

3. In combination, means for supporting tubular work, a grinding wheel,two wheel truing devices, means for effecting a relative traverse ofsaid wheel axially of the work to cause said wheel to grind thev insideof said work, means for con trolling one of said truing devices 'at onetime during an extended portion of such traverse to true said wheel tocylindrical contour, means for controlling the other of said truingdevices and wheel at another time during such extended trav- I erseportion to true said wheel to a convex contour, means for controllingthe path of grinding traverse while said wheel is of cylindrical con-.1

tour to effect a roughing cylindrical grinding cut, and means forcontrolling the path of grinding traverse, while said wheel is of convexconwheel on said shift to traverse work on said support, a plurality ofmechanisms for producing and controlling relative and support, each ofincluding a templet for controlling said feed motions automatically inaccordance with the relative traverse positions v and the contour of thecontrolling template, said templates having and means forselectivelypresenting meet another mechanism in operative feed and controllingposition whereby may be rendered efiective forrthe same work piece eachof said mechanisms with a single chucking of said work piece.'

2. A grindingmachine having a work support, a grinding wheel shaft forsupporting a grinding wheel, means for'reciprocating said wheel shaftjtctraversea' grinding wheel carried by said shaft along work on saidsupport, a plurality of mechof said wheel and the work differentcontrolling contours,

tour to effects finishing grinding cut departingfrom cylindrical at aportion of the work and while the work remains in the same relation tosaid work supporting means as during the roughing cut. i

4. In a grinding machine having a rotary work support, an axiallymovable wheel support rockable about an axis spaced from the axis ofrotation of workon said work support, a grindingwheel carried by saidsupport, meansfor rem rocating said wheel support axially to cause saidwheel to traverse work carried by said work support, a pair of meansselectively operable to control the angular position of said wheelsupport as said wheel support is reciprocated, the means oi said' pairbeing set for different controls, and

a wheel truing device,-and a means corresponding to each'ot said pair ofmeans for causing said truing deviceto true the wheel to a contour, eachdifferent from the other and corresponding to such selection, wherebythe work may be ground first to one contour by the wheel trued to onecontour and then to a diil'erent contour by the wheel trued to adiflerent contour while the work remains in the same relationship tosaid work supporting means.

5. In a'grindingmachine having a rotary work I support, an axiallymovable wheel support rockable about an axis spaced from the axis ofrotation ,of work on said work support, 'a grinding feed motions of saidshaft said controlling mechanisms vices positioned at operative on the;same work piece at wheel carried by said support,-means forreciprocating said wheel support axially to cause said work in prising acarrier for a rotary work support and work support, means for relativelyreciprocating said holder and wheel carriage substantially parallel tosaid axis, a plurality of templates carried by one of said members and afollower for each template carried by the other of said members fortraverse of its respective template during such reciprocation andcontrolling'the transverse position of said carriage during suchreciprocation,

- Y a grinding wheel carriage mounted for relative motion transverse tothe axis of rotation of said and for feeding and retracting motions onswing ing of said arm, a plurality .of pairs of cooperatin'g members,one member of each'pair being a and means for independently adjustingsaid iollowers with respect to their respective templates to bring anyselected one of saidfollowers into operative relation to its templatewhile the others are inoperative, whereby a work piece may be subjectedto grinding operations controlled by a plurality of said templets duringa single chucking. 1

'I. A grinding machine having members comprising a holder for a rotarywork support anda grinding wheel carriage mounted for relative motiontransverse to the axis of rotation of said work support, a grindingwheel mounted on said carriage, means for reciprocating said holdersubstantially parallel to said axis throughout a justing said followerswith respect totheir respective templates to bring any one selectedfollower into operative relation to its template .while the others areinoperative, whereby a work piece may be subjected to grindingoperations controlled by a pluralityof said templets during a singlechucking. I

8. In a grinding machine, a bed, a rotary work support carried by saidbed, anarm mounted on template and the other of. said members being afollower for traversing said template, one of the members of each pairbeing carried by said arm and the other of said members being carried bysaid bed, said arm-carrying members being located at ditjterentdistances from said am axis, and means-for adjusting the bed-carriedmember of each pair into and out of cooperative relation to itscooperating member, whereby any selected one of said pairs of membersmay be made effective to control the angular position of said arm inaccordance with the axial pomtion thereof as determined by the contourof its respective template and a plurality of said pairs of membersmay-be sequentially effective on a work piece during a single chucking.of a work piece.

10. In combination,

said workaholder within a working range and outside of said workingrange in awheel truin range, a plurality of wheel truing tools locatedat difierent axial portions of said truing range,

means. including templates and followers for traversing said templatesas the wheel .traverses, determining the position of said wheeltransverse to its traverse during such traverse, and means for renderingany selected one of said truing tools operative to true the wheel to acontour said bed for pivotal and axial motion with respect to thepivotal axis, a grinding wheelcarried by -said arm for traversing workcarried by said work support on axial motion of said arm and for.feeding'and retracting motions on swinging of said arm, a plurality ofpairs of cooperating members, one member of each pair being a templateand the other of said members being a follower for traversing saidtemplate, one of the members of each pair being carried by said arm andthe otherof said members being carried by said bed, and means foradjusting the bed-carried member of each pair into and out ofcooperative relation to its cooperating member, whereby any selected oneof said pairs of members may be made effective to control the angularposition of said arm in accordance with the axial position thereof asdetermined by the contour of its respective template and a plurality ofsaid pairs of members may be sequentially effective on a work pieceduring a single chucking of a work piece.

9., In a grinding machine, a bed, a rotary work determined by thecontour of the portion of the template controlling the transverseposition of said wheel in that portion ofthe truing range within whichthe selected truing tool is positioned, whereby a. work piece may besubjected" to grinding operations controlled by a plurality of saidtemplets during a single chucking.

11. In' combination, means for supporting work, a grinding wheelcarriage, means for rotarily supporting .a grinding wheel on said car- 7riage at a selected'axial position, means foreffecting a )raverse ofsaid carriage relative to said work support within a working rangewherein said wheelmay operate on work carried by said supporting meansand beyond said working range in one direction in a wheel truing range,a plurality of wheel truing devices located at different axial portionsof said truing range, means ineluding a template and a follower fortraversing said template as the carriage traverses for controlling thetransverse position of said carriage,

and means for rendering any selected one of said devices operative totrue the wheel to a contour determined by the contour of the portion ofthe template controlling the transverse position of the carriage in'thatportion of the truing range during which the grinding wheel is ineffective axial relation to the selected truing device,

whereby a work piece may be subjected to grinding operations controlledby a plurality of said templets during asingle chucking.

12. In combination, means for supporting tu-" bular work, grindingmechanism including an internal grinding wheel, wheel truing meanspositioned to act on said grinding wheel/when said grinding means isretracted axially relative to support carried by said bed, an armmounted on 7 said bed for pivotal and axial motion with rethe work,means for producing relative motion of said work and wheel axially, anda plurality of mechanisms selectively operable tocontrol the position ofsaid wheel transverse to the work axis, each of the controlling meansincluding a former cam and a 'follower'for traversing its respectiveformer cam, each of said former camshaving a means for supporting work,a grinding wheel, means for eflecting a traverse of said wheel relativeto work carried by I lengthwise" portion 'for controlling the positionof said wheel while in grinding relation to the work,

and a lengthwise portion for controlling the position of said wheelwhile said wheel is in operative relation to truing means, said portionsof one of 5 contour.

said former cams being contoured to produce cylindrical-grinding of thework and cylindrical MER'I'ON H. ARMS.

